Conventionally, there has been known display devices using an organic light emitting diode (OLED), a liquid crystal display (LCD), a vacuum fluorescent display, and a field emission display (FED) as display panels for displaying images.
In the flat display panels described above, dots as light emitting units are two-dimensionally arranged, and each dot is made to emit light at a luminance corresponding to display data.
As a light emitting method for displaying an image on the display panel, there are a method (dot driving method) for sequentially controlling the dots to emit light, a method (line driving method) for sequentially controlling lines, each of which has dots linearly arranged, by allowing the dots belonging to each of the lines to simultaneously emit light, a method (frame driving method) for controlling all dots belonging to a frame constituting one screen to simultaneously emit light, and the like.
Further, in Japanese Patent Application Publication No. 2000-306532, there has been proposed a driving technique of increasing a so-called duty cycle by multiple times by arranging dots in a plurality groups of grids and scanning the dots of the respective groups at the same cycle in a rightward direction or leftward direction, in a display device using, e.g., a vacuum fluorescent display (VFD).
In recent years, with an increasing demand for a larger screen and a higher definition image, the number of dots in the display device has also increased dramatically. This also requires a driver circuit capable of driving more dots.
With an increase in the number of dots, in a conventional driving technique, the time for driving one dot becomes short, and the luminance of each dot is set to a high level to obtain an image with high luminance. However, the lifetime of the display panel is shortened by setting the luminance of the dots to a high level. Further, in the case of using the line driving method, the quality of the displayed image deteriorates due to the mutual interference between the lines. In particular, in the display device using OLED, which is drawing attention in view of compact, light weight and the like, these problems are remarkable.